The present invention relates to sheet handling and counting apparatus and more particularly to a novel self-compensating stripper assembly for sheet handling and counting apparatus to facilitate the stripping operation.
High speed document handling and counting apparatus is finding more widespread use, especially in banks and other like institutions where it is desired to count, authenticate and endorse documents such as checks and paper currency both accurately and at high speed.
One such apparatus is disclosed in U.S. Pat. No. 3,771,783 issued Nov. 13, 1973 assigned to assignee of the present application as described therein, the document handling apparatus employs a sheet separating assembly comprised of a drive wheel and a cooperating stripper wheel. The drive wheel rotates in a direction to move the sheets in a forward feed direction. The stripper wheel is rotated so that the peripheral portion which engages the sheet fed to the drive wheel moves in a direction reverse that of the forward feed direction. The coefficient of friction of the peripheries of the drive and stripper wheels are of different values which values are selected to cause the drive wheel to have the prevailing influence upon sheets fed therebetween. However, with respect to double-fed or multiple-fed sheets, the sheet engaging the drive wheel is moved in the forward feed direction while the sheet engaging the stripper wheel is moved in a direction opposite the forward feed direction to thereby assure the feeding of single sheets through the sheet separation assembly.
The stripper assembly thus requires driving means and further is subjected to wearing due to the frictional engagement between the rotating stripper wheel and the sheets being fed thereto.
Also, no means are provided for enabling the stripper wheel to be abruptly displaced relative to the feed wheel due to a jammed condition.
Another technique employed in the prior art for separating sheets utilizes a stationary member having a knife edge positioned above a feed means by a distance sufficient to allow passage of single sheets and insufficient to allow the passage of double fed sheets. Although this technique is effective for stiff and/or thick sheets, such as punch cards, thin, lightweight and fragile documents are highly susceptible to being torn by the stationary member. In the case where two documents are stuck together, the knife edge will often cause one or more of the sheets to be damaged or torn.
Therefore, it is highly desirable to provide means for feeding and separating sheets at high speeds in an accurate manner without damaging the sheets being processed and through the employment of a simple and yet rugged and reliable apparatus.